Investigations of the initial stage of recombinant human-like collagen mineralization

To found the theoretical foundation for applying recombinant human-like collagen (RHLC) to bone tissue engineering, the initial stage of RHLC mineralization was studied for the first time by using Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). SEM images showed that samples of RHLC/calcium phosphate were spongy. TEM images and Selected Area Electron Diffraction (SAED) exhibited that the RHLC fibers in the mineralized samples were surrounded by HA nanocrystals. By comparing the FTIR spectra of RHLC, RHLC/Ca2+ and RHLC/calcium phosphate, it was observed that the peak for amide I shifted to a lower wavenumber indicating that there is chemical interaction between carbonyl groups of RHLC and calcium ions. These results are consistent with previous studies of natural collagen mineralization. It is reasonable to conclude that RHLC can regulate the deposition of HA nanocrystals and may be used in bone tissue engineering.